diff --git a/src/main/java/io/nats/client/support/NatsRequestCompletableFuture.java b/src/main/java/io/nats/client/support/NatsRequestCompletableFuture.java
index 4eab05609..88a18d9a5 100644
--- a/src/main/java/io/nats/client/support/NatsRequestCompletableFuture.java
+++ b/src/main/java/io/nats/client/support/NatsRequestCompletableFuture.java
@@ -12,7 +12,11 @@
  * This is an internal class and is only public for access.
  */
 public class NatsRequestCompletableFuture extends CompletableFuture<Message> {
+
     public enum CancelAction { CANCEL, REPORT, COMPLETE }
+
+    private static final String CLOSING_MESSAGE = "Future cancelled, connection closing.";
+    private static final String CANCEL_MESSAGE = "Future cancelled, response not registered in time, check connection status.";
     private static final long DEFAULT_TIMEOUT = Options.DEFAULT_REQUEST_CLEANUP_INTERVAL.toMillis(); // currently 5 seconds
 
     private final CancelAction cancelAction;
@@ -30,19 +34,25 @@ public NatsRequestCompletableFuture(CancelAction cancelAction, Duration timeout,
 
     public void cancelClosing() {
         wasCancelledClosing = true;
-        completeExceptionally(new CancellationException("Future cancelled, connection closing."));
+        completeExceptionally(new CancellationException(CLOSING_MESSAGE));
     }
 
     public void cancelTimedOut() {
         wasCancelledTimedOut = true;
-        final String message = "Future cancelled, response not registered in time, likely due to server disconnect.";
-        completeExceptionally(useTimeoutException ? new TimeoutException(message) : new CancellationException(message));
+        completeExceptionally(
+            useTimeoutException
+                ? new TimeoutException(CANCEL_MESSAGE)
+                : new CancellationException(CANCEL_MESSAGE));
     }
 
     public CancelAction getCancelAction() {
         return cancelAction;
     }
 
+    public boolean useTimeoutException() {
+        return useTimeoutException;
+    }
+
     public boolean hasExceededTimeout() {
         return System.currentTimeMillis() > timeOutAfter;
     }
diff --git a/src/test/java/io/nats/client/impl/RequestTests.java b/src/test/java/io/nats/client/impl/RequestTests.java
index f87a51960..ca8da444c 100644
--- a/src/test/java/io/nats/client/impl/RequestTests.java
+++ b/src/test/java/io/nats/client/impl/RequestTests.java
@@ -679,8 +679,9 @@ public void testThrowsEmptySubject() {
     }
 
     @Test
-    public void testNatsRequestCompletableFuture() throws InterruptedException {
-        NatsRequestCompletableFuture f = new NatsRequestCompletableFuture(CancelAction.CANCEL, Duration.ofHours(-1), true);
+    public void testNatsRequestCompletableFuture() throws Exception {
+        // coverage for configuration
+        NatsRequestCompletableFuture f = new NatsRequestCompletableFuture(CancelAction.CANCEL, Duration.ofMillis(-1000), true);
         assertEquals(CancelAction.CANCEL, f.getCancelAction());
         assertTrue(f.hasExceededTimeout());
         assertFalse(f.wasCancelledClosing());
@@ -689,17 +690,43 @@ public void testNatsRequestCompletableFuture() throws InterruptedException {
         f.cancelTimedOut(); // not real use, just testing flags
         assertTrue(f.wasCancelledClosing());
         assertTrue(f.wasCancelledTimedOut());
+        assertTrue(f.useTimeoutException());
 
-        f = new NatsRequestCompletableFuture(CancelAction.COMPLETE, Duration.ofHours(-1), true);
+        f = new NatsRequestCompletableFuture(CancelAction.COMPLETE, Duration.ofNanos(0), true);
         assertEquals(CancelAction.COMPLETE, f.getCancelAction());
 
-        f = new NatsRequestCompletableFuture(CancelAction.REPORT, Duration.ofHours(-1), true);
+        f = new NatsRequestCompletableFuture(CancelAction.REPORT, Duration.ofNanos(0), true);
         assertEquals(CancelAction.REPORT, f.getCancelAction());
 
         // coverage for null timeout
         f = new NatsRequestCompletableFuture(CancelAction.CANCEL, null, true);
         Thread.sleep(Options.DEFAULT_REQUEST_CLEANUP_INTERVAL.toMillis() + 100);
         assertTrue(f.hasExceededTimeout());
+
+        f = new NatsRequestCompletableFuture(CancelAction.CANCEL, Duration.ofNanos(0), false);
+        assertFalse(f.useTimeoutException());
+
+        // coverage for behavior
+        NatsRequestCompletableFuture fcf = new NatsRequestCompletableFuture(CancelAction.CANCEL, Duration.ofNanos(0), false);
+        assertFalse(fcf.useTimeoutException());
+        fcf.cancelClosing();
+        assertThrows(CancellationException.class, fcf::get);
+
+        NatsRequestCompletableFuture fct = new NatsRequestCompletableFuture(CancelAction.CANCEL, Duration.ofNanos(0), true);
+        assertTrue(fct.useTimeoutException());
+        fct.cancelClosing();
+        assertThrows(CancellationException.class, fct::get);
+
+        NatsRequestCompletableFuture ftof = new NatsRequestCompletableFuture(CancelAction.CANCEL, Duration.ofNanos(0), false);
+        assertFalse(ftof.useTimeoutException());
+        ftof.cancelTimedOut();
+        assertThrows(CancellationException.class, ftof::get);
+
+        NatsRequestCompletableFuture ftot = new NatsRequestCompletableFuture(CancelAction.CANCEL, Duration.ofNanos(0), true);
+        assertTrue(ftot.useTimeoutException());
+        ftot.cancelTimedOut();
+        ExecutionException ee = assertThrows(ExecutionException.class, ftot::get);
+        assertTrue(ee.getCause() instanceof TimeoutException);
     }
 
     @Test